In recent years the wind power sector has seen a huge expansion owing to the fact that wind energy is a credible alternative to fossil fuels, since it is renewable, available everywhere, and clean; however, conventional wind power assemblies (by which is principally meant the now-classic wind towers with three vanes, which, in industrial terms, effectively monopolize the worldwide scene) present problems of a physical and economic nature which make wind power an inferior energy source or at any rate a parallel one, and in any case not yet a replacement for energy from hydrocarbons.
Every wind power system has, in fact, firstly, the undeniable need to have the broadest possible area for capturing wind, in order to collect the maximum quantity of kinetic energy and have a suitable production; it is further necessary to raise the system as high as possible from the ground so as to intercept wind that is more powerful and dependable. Current wind towers are therefore provided, to this end, with supporting masts of ever-increasing height and diameter, in order to withstand the increased torsional forces, and with vanes of increasing length in order to increase as much as possible the diameter of the single rotor, and thus the wind capture area; unfortunately, however, as the diameter of a rotor increases there is, for the same wind, a proportional decrease in its specific yield, and a proportional increase in the windspeed necessary in order to trigger the rotation. Furthermore, the necessity of making, transporting and raising increasingly big structures has meant an exponential increase of the installation costs. It is also important to add that the vanes of current wind towers are provided with a very sophisticated wing profile that is not only extremely expensive, but also owes its high performance levels to an effect called “lift” that is generated only in the presence of sustained winds. The set of problems mentioned above makes the installation of current wind power systems profitable, and hence possible, only in areas with high average winds and then only if there are significant economic incentives.